The individual components of the skeletal musculature, e.g., muscle units, proprioceptors, connective tissue (including the vasculature and its autonomic innervation), etc.are manifold and intricate, and as a consequence one components is often studied with little regard for the other tissues or structures with which it is intimately related. The present studies are intended 1) to determine the factors, neural and otherwise, that control the differentiation and maintenance of the sensory and motor components of the skeletomotor system, and 2) to attempt to integrate the relationships of these sensory and motor systems with respect to better understanding normal posture and locomotion, physiological tremor and shivering, as well as tremor, rigidity and other dystonias. Additional studies, utilizing "culture" techniques, are aimed at defining the factors and agents responsible for the initiation, maintenance and regions of the central nervous system).